- 23 Mar, 2020 40 commits
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Filipe Manana authored
When doing a fast fsync for a range that starts at an offset greater than zero, we can end up with a log that when replayed causes the respective inode miss a file extent item representing a hole if we are not using the NO_HOLES feature. This is because for fast fsyncs we don't log any extents that cover a range different from the one requested in the fsync. Example scenario to trigger it: $ mkfs.btrfs -O ^no-holes -f /dev/sdd $ mount /dev/sdd /mnt # Create a file with a single 256K and fsync it to clear to full sync # bit in the inode - we want the msync below to trigger a fast fsync. $ xfs_io -f -c "pwrite -S 0xab 0 256K" -c "fsync" /mnt/foo # Force a transaction commit and wipe out the log tree. $ sync # Dirty 768K of data, increasing the file size to 1Mb, and flush only # the range from 256K to 512K without updating the log tree # (sync_file_range() does not trigger fsync, it only starts writeback # and waits for it to finish). $ xfs_io -c "pwrite -S 0xcd 256K 768K" /mnt/foo $ xfs_io -c "sync_range -abw 256K 256K" /mnt/foo # Now dirty the range from 768K to 1M again and sync that range. $ xfs_io -c "mmap -w 768K 256K" \ -c "mwrite -S 0xef 768K 256K" \ -c "msync -s 768K 256K" \ -c "munmap" \ /mnt/foo <power fail> # Mount to replay the log. $ mount /dev/sdd /mnt $ umount /mnt $ btrfs check /dev/sdd Opening filesystem to check... Checking filesystem on /dev/sdd UUID: 482fb574-b288-478e-a190-a9c44a78fca6 [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 257 errors 100, file extent discount Found file extent holes: start: 262144, len: 524288 ERROR: errors found in fs roots found 720896 bytes used, error(s) found total csum bytes: 512 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 123514 file data blocks allocated: 589824 referenced 589824 Fix this issue by setting the range to full (0 to LLONG_MAX) when the NO_HOLES feature is not enabled. This results in extra work being done but it gives the guarantee we don't end up with missing holes after replaying the log. CC: stable@vger.kernel.org # 4.19+ Reviewed-by:Josef Bacik <josef@toxicpanda.com> Signed-off-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Nikolay Borisov authored
Instead of iterating all pending tickets on the normal/priority list to sum their total size the cost can be amortized across ticket addition/ removal. This turns O(n) + O(m) (where n is the size of the normal list and m of the priority list) into O(1). This will mostly have effect in workloads that experience heavy flushing. Signed-off-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
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Roman Gushchin authored
Currently btrfs doesn't provide a migratepage callback for data pages. It means that fallback_migrate_page() is used to migrate btrfs pages. fallback_migrate_page() cannot move dirty pages, instead it tries to flush them (in sync mode) or just fails (in async mode). In the sync mode pages which are scheduled to be processed by btrfs_writepage_fixup_worker() can't be effectively flushed by the migration code, because there is no established way to wait for the completion of the delayed work. It all leads to page migration failures. To fix it the patch implements a btrs-specific migratepage callback, which is similar to iomap_migrate_page() used by some other fs, except it does take care of the PagePrivate2 flag which is used for data ordering purposes. Reviewed-by:
Chris Mason <clm@fb.com> Signed-off-by:
Roman Gushchin <guro@fb.com> Signed-off-by:
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Nikolay Borisov authored
It's no longer used following 30d40577 ("btrfs: reloc: Also queue orphan reloc tree for cleanup to avoid BUG_ON()"), so just remove it. Signed-off-by:
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Nikolay Borisov authored
Currently the non-prefixed version is a simple wrapper used to hide the 4th argument of the prefixed version. This doesn't bring much value in practice and only makes the code harder to follow by adding another level of indirection. Rectify this by removing the __ prefix and have only one public function to release bytes from a block reservation. No semantic changes. Signed-off-by:
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Qu Wenruo authored
When relocating data block groups with tons of small extents, or large metadata block groups, there can be over 200,000 extents. We will iterate all extents of such block group in relocate_block_group(), where iteration itself can be kinda time-consuming. So when user want to cancel the balance, the extent iteration loop can be another target. This patch will add the cancelling check in the extent iteration loop of relocate_block_group() to make balance cancelling faster. Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
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Qu Wenruo authored
When relocating a data extents with large large data extents, we spend most of our time in relocate_file_extent_cluster() at stage "moving data extents": 1) | btrfs_relocate_block_group [btrfs]() { 1) | relocate_file_extent_cluster [btrfs]() { 1) $ 6586769 us | } 1) + 18.260 us | relocate_file_extent_cluster [btrfs](); 1) + 15.770 us | relocate_file_extent_cluster [btrfs](); 1) $ 8916340 us | } 1) | btrfs_relocate_block_group [btrfs]() { 1) | relocate_file_extent_cluster [btrfs]() { 1) $ 11611586 us | } 1) + 16.930 us | relocate_file_extent_cluster [btrfs](); 1) + 15.870 us | relocate_file_extent_cluster [btrfs](); 1) $ 14986130 us | } To make data relocation cancelling quicker, add extra balance cancelling check after each page read in relocate_file_extent_cluster(). Cleanup and error handling uses the same mechanism as if the whole process finished Reviewed-by: -
Qu Wenruo authored
Introduce a new error injection point, should_cancel_balance(). It's just a wrapper of atomic_read(&fs_info->balance_cancel_req), but allows us to override the return value. Currently there are only one locations using this function: - btrfs_balance() It checks cancel before each block group. There are other locations checking fs_info->balance_cancel_req, but they are not used as an indicator to exit, so there is no need to use the wrapper. But there will be more locations coming, and some locations can cause kernel panic if not handled properly. So introduce this error injection to provide better test interface. Reviewed-by:
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Filipe Manana authored
There are a few cases where we don't allow cloning an inline extent into the destination inode, returning -EOPNOTSUPP to user space. This was done to prevent several types of file corruption and because it's not very straightforward to deal with these cases, as they can't rely on simply copying the inline extent between leaves. Such cases require copying the inline extent's data into the respective page of the destination inode. Not supporting these cases makes it harder and more cumbersome to write applications/libraries that work on any filesystem with reflink support, since all these cases for which btrfs fails with -EOPNOTSUPP work just fine on xfs for example. These unsupported cases are also not documented anywhere and explaining which exact cases fail require a bit of too technical understanding of btrfs's internal (inline extents and when and where can they exist in a file), so it's not really user friendly. Also some test cases from fstests that use fsx, such as generic/522 for example, can sporadically fail because they trigger one of these cases, and fsx expects all operations to succeed. This change adds supports for cloning all these cases by copying the inline extent's data into the respective page of the destination inode. With this change test case btrfs/112 from fstests fails because it expects some clone operations to fail, so it will be updated. Also a new test case that exercises all these previously unsupported cases will be added to fstests. Signed-off-by:
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Filipe Manana authored
We can not reflink parts of an inline extent, we must always reflink the whole inline extent. We know that inline extents always start at file offset 0 and that can never represent an amount of data larger then the filesystem's sector size (both compressed and uncompressed). We also have had the constraints that reflink operations must have a start offset that is aligned to the sector size and an end offset that is also aligned or it ends the inode's i_size, so there's no way for user space to be able to do a reflink operation that will refer to only a part of an inline extent. Initially there was a bug in the inlining code that could allow compressed inline extents that encoded more than 1 page, but that was fixed in 2008 by commit 70b99e69 ("Btrfs: Compression corner fixes") since that was problematic. So remove all the extent cloning code that deals with the possibility of cloning only partial inline extents. Reviewed-by:
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Filipe Manana authored
The reflink code is quite large and has been living in ioctl.c since ever. It has grown over the years after many bug fixes and improvements, and since I'm planning on making some further improvements on it, it's time to get it better organized by moving into its own file, reflink.c (similar to what xfs does for example). This change only moves the code out of ioctl.c into the new file, it doesn't do any other change. Reviewed-by:
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Gustavo A. R. Silva authored
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero." [1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by:Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by:
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Gustavo A. R. Silva authored
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero." [1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: -
Gustavo A. R. Silva authored
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero." [1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: -
Madhuparna Bhowmik authored
The space_info list is normally RCU protected and should be traversed with rcu_read_lock held. There's a warning [29.104756] WARNING: suspicious RCU usage [29.105046] 5.6.0-rc4-next-20200305 #1 Not tainted [29.105231] ----------------------------- [29.105401] fs/btrfs/block-group.c:2011 RCU-list traversed in non-reader section!! pointing out that the locking is missing in btrfs_read_block_groups. However this is not necessary as the list traversal happens at mount time when there's no other thread potentially accessing the list. To fix the warning and for consistency let's add the RCU lock/unlock, the code won't be affected much as it's doing some lightweight operations. Reported-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> Reviewed-by:
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Nikolay Borisov authored
No need to add a level of indirection for hiding a simple 'if'. Open code insert_extent_backref in its sole caller. No functional changes. Reviewed-by:
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Nikolay Borisov authored
relocate_tree_blocks calls get_tree_block_key for a block iff that block has its ->key_ready equal false. Thus the BUG_ON in the latter function cannot ever be triggered so remove it. Reviewed-by:
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David Sterba authored
The validation follows the same steps for all three block group types, the existing helper validate_convert_profile can be enhanced and do more of the common things. Reviewed-by:
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David Sterba authored
Now that csum_tree_block is not returning any errors, we can make csum_tree_block return void and simplify callers. Reviewed-by:
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David Sterba authored
Thw whole point of csum_tree_block is to iterate over all extent buffer pages and pass it to checksumming functions. The bytes where checksum is stored must be skipped, thus map_private_extent_buffer. This complicates further offset calculations. As the first page will be always present, checksum the relevant bytes unconditionally and then do a simple iteration over the remaining pages. Reviewed-by:
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David Sterba authored
There's an unnecessary indirection in the checksum definition table, pointer and the string itself. The strings are short and the overall size of one entry is now 24 bytes. Reviewed-by:
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Nikolay Borisov authored
Having btrfs_alloc_chunk doesn't bring any value since it encapsulates a lockdep assert and a call to find_next_chunk. Simply rename the internal __btrfs_alloc_chunk function to the public one and remove it's 2nd parameter as all callers always pass the return value of find_next_chunk. Finally, migrate the call to lockdep_assert_held so as to not lose the check. Signed-off-by:
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Josef Bacik authored
I noticed while running my snapshot torture test that we were getting a lot of metadata chunks allocated with very little actually used. Digging into this we would commit the transaction, still not have enough space, and then force a chunk allocation. I noticed that we were barely flushing any delalloc at all, despite the fact that we had around 13gib of outstanding delalloc reservations. It turns out this is because of our btrfs_calc_reclaim_metadata_size() calculation. It _only_ takes into account the outstanding ticket sizes, which isn't the whole story. In this particular workload we're slowly filling up the disk, which means our overcommit space will suddenly become a lot less, and our outstanding reservations will be well more than what we can handle. However we are only flushing based on our ticket size, which is much less than we need to actually reclaim. So fix btrfs_calc_reclaim_metadata_size() to take into account the overage in the case that we've gotten less available space suddenly. This makes it so we attempt to reclaim a lot more delalloc space, which allows us to make our reservations and we no longer are allocating a bunch of needless metadata chunks. CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
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Filipe Manana authored
During unmount we can have a job from the delayed inode items work queue still running, that can lead to at least two bad things: 1) A crash, because the worker can try to create a transaction just after the fs roots were freed; 2) A transaction leak, because the worker can create a transaction before the fs roots are freed and just after we committed the last transaction and after we stopped the transaction kthread. A stack trace example of the crash: [79011.691214] kernel BUG at lib/radix-tree.c:982! [79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G W 5.6.0-rc2-btrfs-next-54 #2 (...) [79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs] [79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170 (...) [79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293 [79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0 [79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0 [79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000 [79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001 [79011.709270] FS: 0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000 [79011.710699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0 [79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [79011.715448] Call Trace: [79011.715925] record_root_in_trans+0x72/0xf0 [btrfs] [79011.716819] btrfs_record_root_in_trans+0x4b/0x70 [btrfs] [79011.717925] start_transaction+0xdd/0x5c0 [btrfs] [79011.718829] btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs] [79011.719915] btrfs_work_helper+0xaa/0x720 [btrfs] [79011.720773] process_one_work+0x26d/0x6a0 [79011.721497] worker_thread+0x4f/0x3e0 [79011.722153] ? process_one_work+0x6a0/0x6a0 [79011.722901] kthread+0x103/0x140 [79011.723481] ? kthread_create_worker_on_cpu+0x70/0x70 [79011.724379] ret_from_fork+0x3a/0x50 (...) The following diagram shows a sequence of steps that lead to the crash during ummount of the filesystem: CPU 1 CPU 2 CPU 3 btrfs_punch_hole() btrfs_btree_balance_dirty() btrfs_balance_delayed_items() --> sees fs_info->delayed_root->items with value 200, which is greater than BTRFS_DELAYED_BACKGROUND (128) and smaller than BTRFS_DELAYED_WRITEBACK (512) btrfs_wq_run_delayed_node() --> queues a job for fs_info->delayed_workers to run btrfs_async_run_delayed_root() btrfs_async_run_delayed_root() --> job queued by CPU 1 --> starts picking and running delayed nodes from the prepare_list list close_ctree() btrfs_delete_unused_bgs() btrfs_commit_super() btrfs_join_transaction() --> gets transaction N btrfs_commit_transaction(N) --> set transaction state to TRANTS_STATE_COMMIT_START btrfs_first_prepared_delayed_node() --> picks delayed node X through the prepared_list list btrfs_run_delayed_items() btrfs_first_delayed_node() --> also picks delayed node X but through the node_list list __btrfs_commit_inode_delayed_items() --> runs all delayed items from this node and drops the node's item count to 0 through call to btrfs_release_delayed_inode() --> finishes running any remaining delayed nodes --> finishes transaction commit --> stops cleaner and transaction threads btrfs_free_fs_roots() --> frees all roots and removes them from the radix tree fs_info->fs_roots_radix btrfs_join_transaction() start_transaction() btrfs_record_root_in_trans() record_root_in_trans() radix_tree_tag_set() --> crashes because the root is not in the radix tree anymore If the worker is able to call btrfs_join_transaction() before the unmount task frees the fs roots, we end up leaking a transaction and all its resources, since after the call to btrfs_commit_super() and stopping the transaction kthread, we don't expect to have any transaction open anymore. When this situation happens the worker has a delayed node that has no more items to run, since the task calling btrfs_run_delayed_items(), which is doing a transaction commit, picks the same node and runs all its items first. We can not wait for the worker to complete when running delayed items through btrfs_run_delayed_items(), because we call that function in several phases of a transaction commit, and that could cause a deadlock because the worker calls btrfs_join_transaction() and the task doing the transaction commit may have already set the transaction state to TRANS_STATE_COMMIT_DOING. Also it's not possible to get into a situation where only some of the items of a delayed node are added to the fs/subvolume tree in the current transaction and the remaining ones in the next transaction, because when running the items of a delayed inode we lock its mutex, effectively waiting for the worker if the worker is running the items of the delayed node already. Since this can only cause issues when unmounting a filesystem, fix it in a simple way by waiting for any jobs on the delayed workers queue before calling btrfs_commit_supper() at close_ctree(). This works because at this point no one can call btrfs_btree_balance_dirty() or btrfs_balance_delayed_items(), and if we end up waiting for any worker to complete, btrfs_commit_super() will commit the transaction created by the worker. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: -
Naohiro Aota authored
This function finally factor out prepare_allocation() form find_free_extent(). This function is called before the allocation loop and a specific allocator function like prepare_allocation_clustered() should initialize their private information and can set proper hint_byte to indicate where to start the allocation with. Reviewed-by:
Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by:
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Naohiro Aota authored
LOOP_NO_EMPTY_SIZE is solely dedicated for clustered allocation. So, we can skip this stage and give up the allocation. Signed-off-by:
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Naohiro Aota authored
Factor out chunk_allocation_failed() from find_free_extent_update_loop(). This function is called when it failed to allocate a chunk. The function can modify "ffe_ctl->loop" and return 0 to continue with the next stage. Or, it can return -ENOSPC to give up here. Reviewed-by:
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Naohiro Aota authored
Now that, we don't use last_ptr and use_cluster in the function. Drop these arguments from it. Reviewed-by:
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Naohiro Aota authored
Factor out found_extent() from find_free_extent_update_loop(). This function is called when a proper extent is found and before returning from find_free_extent(). Hook functions like found_extent_clustered() should save information for a next allocation. Reviewed-by:
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Naohiro Aota authored
Factor out release_block_group() from find_free_extent(). This function is called when it gives up an allocation from a block group. Each allocation policy should reset its information for an allocation in the next block group. Reviewed-by:
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Naohiro Aota authored
Now that, find_free_extent_clustered() and find_free_extent_unclustered() can access "last_ptr" from the "clustered" variable, we can drop it from the arguments. Reviewed-by:
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Naohiro Aota authored
Factor out do_allocation() from find_free_extent(). This function do an actual extent allocation in a given block group. The ffe_ctl->policy is used to determine the actual allocator function to use. Reviewed-by:
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Naohiro Aota authored
Move "last_ptr" and "use_cluster" into struct find_free_extent_ctl, so that hook functions for clustered allocator can use these variables. Reviewed-by:
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Naohiro Aota authored
This commit moves hint_byte into find_free_extent_ctl, so that we can modify the hint_byte in the other functions. This will help us split find_free_extent further. This commit also renames the function argument "hint_byte" to "hint_byte_orig" to avoid misuse. Reviewed-by:
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Naohiro Aota authored
This commit introduces extent allocation policy for btrfs. This policy controls how btrfs allocate an extents from block groups. There is no functional change introduced with this commit. Reviewed-by:
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Naohiro Aota authored
Currently, we ignore a device whose available space is less than "BTRFS_STRIPE_LEN * dev_stripes". This is a lower limit for current allocation policy (to maximize the number of stripes). This commit parameterizes dev_extent_min, so that other policies can set their own lower limitat to ignore a device with insufficient space. Reviewed-by:
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Naohiro Aota authored
Factor out create_chunk() from __btrfs_alloc_chunk(). This function finally creates a chunk. There is no functional changes. Reviewed-by:
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Naohiro Aota authored
Factor out decide_stripe_size() from __btrfs_alloc_chunk(). This function calculates the actual stripe size to allocate. decide_stripe_size() handles the common case to round down the 'ndevs' to 'devs_increment' and check the upper and lower limitation of 'ndevs'. decide_stripe_size_regular() decides the size of a stripe and the size of a chunk. The policy is to maximize the number of stripes. This commit has no functional changes. Reviewed-by:
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Naohiro Aota authored
Factor out gather_device_info() from __btrfs_alloc_chunk(). This function iterates over devices list and gather information about devices. This commit also introduces "max_avail" and "dev_extent_min" to fold the same calculation to one variable. This commit has no functional changes. Reviewed-by:
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Naohiro Aota authored
Factor out init_alloc_chunk_ctl() from __btrfs_alloc_chunk(). This function initialises parameters of "struct alloc_chunk_ctl" for allocation. init_alloc_chunk_ctl() handles a common part of the initialisation to load the RAID parameters from btrfs_raid_array. init_alloc_chunk_ctl_policy_regular() decides some parameters for its allocation. The last "else" case in the original code is moved to __btrfs_alloc_chunk() to handle the error case in the common code. Replace the BUG_ON with ASSERT() and error return at the same time. Reviewed-by:
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